It has long been desired to maximize fuel economy, power and driveability in gasoline powered vehicles while enhancing acceleration, reducing emissions, and preventing hesitation. While it is known to enhance gasoline powered engine performance by employing dispersants to keep valves and fuel injectors clean in port fuel injection engines, such gasoline dispersants are not necessarily effective for cleaning up direct fuel injected engines.
With the current use of direct fuel injected gasoline engines, dispersants that previously could have been used for gasoline engines do not work for both direct injected engines and port fuel injected engines. For example Mannich dispersants that were used in port fuel injected gasoline engines fail to provide suitable improvement in direct injected gasoline engines.
Over the years, dispersant compositions for gasoline fuels have been developed. Dispersant compositions known in the art for use in fuels include compositions that may include polyalkylene succinimides, polyalkenepolyamines, polyetheramines, and polyalkyl substituted Mannich compounds. Dispersants are suitable for keeping soot and sludge suspended in a fluid, however the foregoing dispersants are not particularly effective for cleaning surfaces of direct fuel injected engines.
Hence, fuel compositions for direct fuel injected engines often produce undesirable deposits in the internal engine surfaces and fuel filters. Accordingly, improved compositions that can prevent deposit build up, maintaining “as new” cleanliness for the vehicle life are desired. Ideally, the same composition that can clean up dirty fuel injectors restoring performance to the previous “as new” condition would be equally desirable and valuable in the attempt to reduce air borne exhaust emissions and to improve the power performance of the engines.
In accordance with the disclosure, exemplary embodiments provide a fuel soluble additive for a gasoline engine, a gasoline fuel containing the additive, a method for improving performance of fuel injectors and a method for cleaning fuel injectors for a gasoline engine. The fuel soluble additive includes a quaternary ammonium salt derived from an amido amine containing at least one tertiary amino group and an epoxide, in the presence of a proton donor. The amido amine is made in a reaction medium that is substantially devoid of an acylating agent.
Another embodiment of the disclosure provides a gasoline fuel composition that includes from 5 to about 100 ppm based on a total weight of the fuel composition of a quaternary ammonium salt derived from an amido amine containing at least one tertiary amino group and an epoxide, in the presence of a proton donor selected from a carboxylic acid and an alkyl phenol. The amido amine is made in a reaction medium that is substantially devoid of an acylating agent.
A further embodiment of the disclosure provides a method improving the injector performance of a direct fuel injected gasoline (DIG) engine. The method includes operating the engine on a fuel composition containing a major amount of gasoline fuel and from about 5 to about 100 ppm by weight based on a total weight of the fuel composition of a quaternary ammonium salt derived from an amido amine containing at least one tertiary amino group and an epoxide, in the presence of a proton donor selected from a carboxylic acid and an alkyl phenol. The amido amine is made in a reaction medium that is substantially devoid of an acylating agent.
A further embodiment of the disclosure provides a method of operating a direct fuel injected gasoline (DIG) engine. The method includes combusting in the engine a fuel composition comprising a major amount of gasoline fuel and from about 5 to about 100 ppm by weight based on a total weight of the fuel composition of a quaternary ammonium salt derived from an amido amine containing at least one tertiary amino group and an epoxide, in the presence of a proton donor selected from a carboxylic acid and an alkyl phenol. The amido amine is made in a reaction medium that is substantially devoid of an acylating agent.
In another embodiment of the fuel additive is an amido amine derived from a fatty acid.
An advantage of the fuel additive described herein is that the additive may not only reduce the amount of deposits forming on fuel injectors, but the additive may also be effective to clean up dirty fuel injectors sufficient to provide improved engine performance.
Another advantage of the fuel additive described herein is that it may be used at a much lower concentration than a quaternary ammonium salt derived from an acylating agent, yet provide better injector cleanliness performance than conventional quaternary ammonium salts made from amines derived from acylating agents.
Additional embodiments and advantages of the disclosure will be set forth in part in the detailed description which follows, and/or can be learned by practice of the disclosure. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed.